Colonial Academic Alliance Undergraduate Research Journal
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Open Access journal
ISSN (Print) 2165-7076
Published by Colonial Academic Alliance [1 journal]
- CSI-Pi: A novel automated secure solution to interpret on-site
Authors: Subrata Acharya Dr. et al.
Abstract: Illicit drug evidence constitutes a vast majority of chemical evidence collected from crime scenes. However, determining which drug is seized is not a trivial task as most are white powders. Since their introduction, colorimetric chemical detection tests, also referred to as presumptive drug tests based on their tentative determination of unknown substances, aid in the on-scene differentiation of drug material with a rapid color change within 1-2 minutes. These colorimetric tests are an important tool used in crime scene investigation and for obtaining a search warrant to find illegal drug labs and drug distributors. However, both positive and negative color interpretation is often reported differently depending upon the user and two analysts may describe the same color differently, e.g., "brilliant greenish blue" vs. "strong greenish blue". Moreover, the high rate of false positives and working color memory limit the effectiveness of these manual tests. To this effect, this research reduces the subjective interpretation and reporting with regard to color in these tests by offering users with a new platform/technology in the form of a Raspberry Pi (standalone) application that "reads" the color of the presumptive drug test, searches and matches the color using a pre-built library database, and reports accuracy (%) matches for further laboratory evaluation.
PubDate: Thu, 24 Mar 2016 12:07:47 PDT
- Application of High-field NMR Spectroscopy for Differentiating Cathinones
for Forensic Identification
Authors: Jessica N. Krummel et al.
Abstract: Synthetic cathinone family compounds or designer drugs are the major naturally-occurring psychostimulant and hallucinogenic designer drugs that are used illegally in the United States and several other countries for their cocaine, methylenedioxymethamphetamine (MDMA), and amphetamine-like effects. Since 2009, forensic labs have identified synthetic cathinones in an increasing percentage of cases. One of the problems crime labs face when analyzing submitted drug evidence is that the samples are often mixtures and can contain one or more of several cutting agents. In this work, we demonstrate the utility of high-field 1H-NMR as a screening tool to detect cathinones in the presence adulterants or “cutting agents”. We collected 1H- and 13C-NMR spectra of three structurally distinct cathinones: alpha-piperidinobutiophenone, alpha-pyrrolidinopentiothiophenone, and pentylone. The spectra were collected with the pure cathinones and in the presence of a cutting agent, commercial powdered sugar (sucrose), and in two solvents. Without knowing the mixture components, it is impossible to select a solvent that will (ideally) only dissolve the drug of interest for interpretation. High-field NMR can be used to provide a spectral assignment and structure determination of a sample of an unknown cathinone and spectral signatures for screening, even when the cutting agent is also very soluble as observed when the solvent was D2O. The NMR spectra provide evidence that rapidly acquired 1H spectra can be used to strongly indicate the identity of cathinones in a sample if they are present in a library.
PubDate: Thu, 24 Mar 2016 12:07:34 PDT